“There’s already this kind of demands for Russian help,” he added as well as “the kind of provocations that we saw in eastern Ukraine.”

McCain also cast doubt as to whether Putin will not move into eastern Ukraine, saying the Russian president “still has forces masked around it.”

He warned of the possibility of further violence in Crimea, saying there are still thousands of Ukrainian troops in Crimea. The senator also suggested that Putin could “be using same the same kind of strategy” in Latvia, noting the country also has a large Russian population.

“I don’t know how far he goes,” McCain said, adding it depends on the U.S. and European response, which he criticized as “unbelievably weak.”